Neodymium magnets properties
发布时间: 2010-02-04 15:57 | 作者: aloys
Some important properties used to compare permanent magnets are: remanence (Mr), which measures the strength of the magnetic field; coercivity (Hci), the material’s resistance to becoming demagnetized; energy product (BHmax), the density of magnetic energy; and Curie temperature (TC), the temperature at which the material loses its magnetism. Neodymium magnets have higher remanence, much higher coercivity and energy product, but often lower Curie temperature than other types. Neodymium is alloyed with terbium and dysprosium in order to preserve its magnetic properties at high temperatures.[1] The table below compares the magnetic performance of neodymium magnets with other types of permanent magnets.
| Magnets | Mr (T) | Hci (kA/m) | BHmax (kJ/m3) | TC (°C) |
|---|---|---|---|---|
| Nd2Fe14B (sintered) | 1.0–1.4 | 750–2000 | 200–440 | 310–400 |
| Nd2Fe14B (bonded) | 0.6–0.7 | 600–1200 | 60–100 | 310–400 |
| SmCo5 (sintered) | 0.8–1.1 | 600–2000 | 120–200 | 720 |
| Sm(Co, Fe, Cu, Zr)7 (sintered) | 0.9–1.15 | 450–1300 | 150–240 | 800 |
| Alnico (sintered) | 0.6–1.4 | 275 | 10–88 | 700–860 |
| Sr-ferrite (sintered) | 0.2–0.4 | 100–300 | 10–40 | 450 |
